(NBC NEWS) -- Enjoy that turkey while you can - someday, it might be grown in a test tube.

With
scientists worried that the world's increasing population could lead to
a food crisis, lab-coated chefs of tomorrow have begun serving up a
buffet of alternative food choices, not just for meeting food needs in
the hungry developing world, but for healthier, cheaper, more
sustainable eating in nations like the U.S.

Lab-grown meat,
exotic protein sources, and 3-D printing all have the potential to
change the way Americans eat. NBC News checked with experts about what
might replace cranberry sauce and stuffing on Thanksgiving tables in
just a few decades.

Testtube turkey?In August, scientists and world-class chefs joined forces to cook and taste
a beef patty made from lab-grown tissue. Will we be serving test tube
turkey for Thanksgiving one day? "It's possible to do it," said Mark Post, professor of physiology at Maastricht University in the Netherlands, who is engineering the tissue.

While
it is "easy" to grow the meat in shreds to press together into a patty,
the hard part will be fashioning a bird-shaped product that can be
stuffed and carved, he said.

The challenge is building plumbing
through thick chunks of tissue that can nourish deep-set cells.
Bioengineers who are building replacement organs like livers and kidneys
in the lab for medical use are trying to clear the same hurdle.

Post
says that his technique can be used to grow any kind of meat, from tuna
to turkey. But, because of the environmental footprint of rearing farm
animals, "the biggest game to be had is beef."

As for whether the
final product will ever taste like it grew up on the farm, "I guess
it's a gamble," Post said, after all his beef patty's flavor "could
still be improved." How? "If we keep the cells and let them make the
tissue like it is in the animal, it will hopefully create the same
taste."

Bug casserole?
In a few years, don't be too surprised if green bug casserole is a Thanksgiving staple.

Over
1,900 species of insects have been identified as edible, the U.N. said
in a report published in May. Popular crunchy munchies include: beetles,
caterpillars, wasps and ants, as well as cicadas, termites, and
dragonflies.

Though an estimated 80 percent of the world eats bugs, they're still practically unknown in American cuisine.

A
Brooklyn startup called Exo is crafting protein bars with flour milled
from slow-roasted crickets. The bars - each containing 25 insects - come
in three flavors: cacao nut, PB&J and cashew ginger Moroccan spice.
A Kickstarter funding campaign floated by the two co-founders that
aimed to raise $20,000 ended up netting more than double that amount.
Out west, San Francisco-based Chirp hopes to be "America's first producer of sustainably grown, edible insects."

3-D printed pie?
In May, NASA funded a project
that's developing 3-D printing technology that can create food during
space travel. Pizzas will be first up because their layered design -
dough, sauce, cheese - makes it an ideal candidate for printing.

But desserts are likely to be among the printed foods we'll be eating first. In fact, you can try one today.

Fab@Home,
a research group at Cornell University, started out printing layers of
gooey chocolate that hardened into shapes, and has now spun off a
startup called Seraph Robotics to develop its food printing technology.

At the Sugar Labs in Los Angeles, a duo of confectioners specialize in all-sugar cake decorations that they print out on a device that resembles a Xerox machine.
It's likely that a layered pie, or at least a perfectly woven lattice
crust popped fresh from the printer, is just a few years away.

But
folks who are familiar with eating trends in the U.S. say that much of
America won't be tempted by 3-D printed dessert, whether the filling is
apple, pumpkin or pecan.

"Anything That Moves" author Dana Goodyear has observed that "throwback" concepts like foraging and the paleo diet
are gaining ground. American food has come to be known as processed and
industrial, and Americans - those that can afford it anyway - are
trying to distance themselves from the idea.

"People are more
mistrustful than ever of that kind of processing and technology," she
told NBC News. "They want to feel closer to their food not removed from
it." If technology is being explored in new ways in this country, it
tends to be older ideas, like pickling and canning, that are sticking.

"The future of food does not lie in futuristic technology," she said, "it lies in the technologies of the past."

Adventurous gourmand Andrew Zimmern,
host of Bizarre Foods on the Travel Channel, told NBC News that he
wants the food of the future "to be curated by family farmers."

"I don't believe that the future of food is done by men in white coats," he said.

Not entirely, anyway - he does think technology has an important role to play, calling Post's lab-grown burger and the plant-based egg substitute made at Hampton Creek Foods in San Francisco "gigantic first steps."

Facing
the food problems of the future might mean rethinking our relationship
with technology, but also tempering our expectations of time-tested
table traditions.

Yet, as Zimmern put it, "for some reason we're hung up on the turkey idea."